The emergence of DNA arrays has revolutionized gene expression studies by providing a means to measure mRNA levels for thousands of genes simultaneously. Array approaches are rapidly becoming a method of choice for large-scale gene expression studies and have been used successfully in systems from bacteria to mammals. However, a major bottleneck is the interpretation of the data produced. While it is possible to obtain image analysis software or services for the analysis of DNA arrays from a number of vendors, current software and analysis techniques often fall short of providing the end user with meaningful output. This proposal seeks to expand the utility of a software package developed at the University of Washington which incorporates unique algorithms for statistical analysis of expression array data. The outcome of this proposal will be the commercialization of a software package the greatly increases the ability of biology researchers to extract meaningful data from expression arrays. PROPOSED COMMERCIAL APPLICATIONS: The proposed research will result in the development of a commercial version of software for the analysis of expression arrays that incorporates unique error analysis and data normalization capabilities. Expression arrays technologies and associated software represent the fastest growing market segment of biological research today. We believe that proposed data analysis package can capture a significant fraction of the market for expression array software.